these kinds of questions are why I've starting studying sciences again (at the ripe old age of 44 - good number, 44, if you're into numerology at
all, but that's a WHOLE other topic, and I sideline here)
I remember hearing that
1. there are mathematically either 10 or 11 dimensions (we live in 4 - 3 spatial, 1 is time) - the jury is still out on that one
2. atoms are mostly "empty space", and we can only deal with electrons in probabilities - they are dual in nature, having both particle-like (mass,
for e.g.) and wave-like (constructive/destructive interference, for e.g.) properties
in other words, as my last term chemistry prof. said, "we really don't know what electrons are" ... everything is just theories, in fact, what I
would call hypotheses, as they are not (and so far cannot be) proven
this kind of makes me feel like

and also like
so I wonder if this dark matter is all these other dimensions, the ones we can't see. if you've ever seen Carl Sagan's flatland analogy, it's
about viewing 3 physical dimensions from a 4th, higher, dimension. a being in that 4th physical dimension could easily see all of our 3rd physical
dimension, but we, being "stuck" in the dimensions we can experience, can't actually see or experience that 4th physical dimension. was quite the
awakening for me.
so these higher dimensions... they must be "somewhere" right? and it seems that everything proven mathematically, if it is actually proven and not
fuddled with, turns out to be true - the laws we know have all been derived mathematically. (God I love math)
so I don't find the idea of dark matter to be a fantastical idea, and if the math doesn't work, then they just haven't found the real, elegant,
solution yet. and yes, if one of the components of the formula fails, then the rest has to be reworked. it doesn't mean the basic precept doesn't
have some merit.
for anyone who wants to watch it.. here's that Carl Sagan flatland analogy